Doepfer

Hi Levka

> I do not yet understand completely what Florian means by this;
> Florian; Could you perhaps elaborate a little on this ? 
Ok, but it will be a little bit longish...

Originally an arpeggiator as in Roland Jupiter Series, in SH101 or in 
the Korg Monopoly/Polysix was a simply "misusage" of the keyboard 
scanning electronics. The keyboard of these synths is like a matrix 
scanner. The electronics send addresses (usally 6Bit) in a certain order 
to this matrix, read the data (=pressed keys) from this matrix into a 
buffer, and distribute these (key-)data from the buffer to the sound 
generation.

Usually this reading from the buffer is very(!) fast (at some hundered 
kHz rate). For arpeggiating the buffer is simply read slowly at the rate 
of the (internal or external) clock of the arpeggio.
So at each trigger of the clocksignal provides the next key data to the 
sound generation.

For up, down, up/down arpeggios you simply change the way the matrix of 
the keyboard is addressed. whether the adresses are counted up or down 
or....

This is the classic arppeggio function in basic.

Now you may imagine, that it would be great to have influence on the 
address data of the keyboard scanner. Example: normally the order of the 
notes are
  adresse 000 001 010 011 100 101 110 111  (order= a0 a1 a2)
  notes    c   c#  d   d#  e   f   f#  g
If I press a c-major the order of the notes in the buffer will be
"c e g". A c-sus9 will be "c d f g"

Now i simply invert adress a1:
  adresse 010 011 000 001 110 111 100 101
  notes    d   d#  c   c#  f#  g   e   f
Now the order of the notes in the buffer (and the order of an arpeggio) 
will be "c g e". The c-sus9 is now "d c g f"

You see that a simple conversion of the address data does create 
complete new arpeggio patterns. Imagine what is possible, if you do such 
conversion depending on other sequencings, on states of some 
controlvoltages or what ever...



I know, that a MIDI based arpeggiator system would have to simulate 
this, but I think, it would be worth the effort :-)



Florian